EOP determination from observations of Russian VLBI-network «QUASAR»

A.Finkelstein, A.Ipatov, S. Smolentsev, A.Salnikov, I.Surkis,I. Gayazov, E. Skurikhina, S.Kurdubov,

I.Rahimov, A.Dyakov, R.Sergeev, V.Shpilevsky

Institute of Applied Astronomy RAS

7th IVS General Meeting "Launching the Next-Generation IVS Network"

Madrid (Spain), March 4-9 2012

Institute of Applied Astronomy RAS

«QUASAR» NETWORK2015×4282×4405 км

“There is no national science, as there is no national multiplication table.”

(Anton Chekhov)

GLONASS support contribution to station positions appointment contribution to sources posinions monitoring for

ICRF contribution to IVS EOP time series for

densification

This work is of very importance for:

“QUASAR” COMPLEX COMPONENTS:

• Three observatories: «Svetloe», «Zelenchukskaya», «Badary»• IAA correlator center (schedule, correlation

data treatment)• IAA technical Consulate – obs. plan for

year, month• IAA technology center• IAA AC

Svetloe operable :1999,IVS obs:2003, QUASARobs:2006

Zelenchukskaya operable :2001,IVS obs: 2005 (end), QUASAR-obs: 2006

Badary operable :2005,IVS obs:2007, QUASAR-obs : 2006

• 32 m radio telescope, equipped with low noise receivers,

• frequency and time keeping system with H-masers (VCH-1003M),

• local geodetic network,

• control computers, local computer

• recording terminals Mark5B+,

• DAS R1002M (digital back end)

STATIONS EQUIPMENT

Ru-U Ru-Estations Bd Zc(Sv) BdZcSv

Duration, hours 1 24

aim dUT1 EOP (Xp, Yp, dUT1, Xc,Yc)

Turn-around time 2 hours 2-5 days

Data transfer e-vlbi shipping

Frequency, start time

weekly, Friday 20 UT weekly, Friday 22UT

scheduling SKED (IAA), X/S, 1min159 sources, > 0.25 J

SKED (IAA), X/S, 1min 63 sources, > 0.5 J

bandwidth 8 MGz 16 MGz

Data sampling 1 bit 1 bit

Data rate 256 Mb/s 512 Mb/c

Number of scans 20 330-350

Number of obs. 20 ~1000

DOMESTIC VLBI PROGRAMS

DOMESTIC SESSIONS

Ru-U Ru-E

Sv Zc Bd Sv Zc Bd

2006 6 6 9 9 9

2007 10 12 17 9 9 9

2008 18 15 18 14 14 14

2009 13 26 30 23 23 23

2010 3 50 50 20 20 20

2011 5 65 65 49 49 49

2012 51(1) 51(8) 51(7) 51(5) 51(5) 51(5)

new radio sources set Ru-E (63 sources, > 0.5 J)

new radio sources set Ru-U (159 sources, > 0.25 J)

The main steps at the development Russian Domestic VLBI observations:

• 2005 first VLBI experiments on X-band, ionosferic delay account - from TEC.• Since Auguest 2006 - start regular QUASAR network observations, biweekly with S2 registrator, MicroPARSEC 3-station correlator• 2009 - Mark5b since February, weekly observations - first attempts were made, ARC correlator Mark5B• April 2009: first e-vlbi experiment, since September 2009 - e-vlbi data transfer on regular base for 1-hour Ru-U sessions. Weekly Ru-E and Ru-U sessions on regular base since July 2010 (after Svetloe repair works).• New DAS - first experiment (May 2011), IVS-R4 sess.• Oct.2011 DAS P1002M – Sv, Bd, Zc• Since Nov. 2011 – observations with “RadioAstron”

IAA correlator ARC

• 2006-2008 3-station IAA correlator MicroPARSEC , S2

• 2009 2 st. Correlator IAA ARC, Mark5B

• 2010: 6-station correlator IAA ARC

Svetloe: 2006: reconstruction

1. rail reconstruction Sv: 2006, Zc, Bd – 2007

The antenna rail was reconstructed by adding a steel supporting construction and rebuilding the concrete under it.

Nov.2009 – Jun. 2010 – SVETLOE no operableantenna repair works for steel construction

suppporting, summer 2010 – prophylactic works for Badary,

Zelenchukskaya

VLBI data analysis

• QUASAR software• OCCAM/GROSS (for results verification)• Reduction – IERS Conventions • catalogues: from QUASAR global solution• standard parametrization• tropospheric gradients are not estimated• Ru-U sessions - in automatic mode

RuE-IERS 08 C04

Ru-U-IERS 08 C04

e-vlbi

TEST FOR EOP ACCURACY COMPARISON

For Ru-E, we extract observations for BdSvZc from IVS-R4 sessions

For Ru-U comparison we used IVS-Int2 sessions for 2011 WzTs

EOP time series accuracy (rms (EOP(IAA) – IERS 08 C04))

Domestic sessions IVS-R4 (SvZcBd)N sessions

2011.2-2012.2

rms N sessions2007-2011

rms

dUT1, Int, µs 53 59 125 37

Xp, mas 30 0.72 34 0.73

Yp, mas 30 1.13 34 1.13

dUt, µs 30 35 34 37

Xc, mas 30 0.41 34 0.29

Yc, mas 30 0.39 34 0.34

TIME SERIES OF BASELINES LENGTH

TROPOSPHERIC PARAMETERS WZD, TZD

CONCLUSION REMARKS

• Problem: ~ only 70% observationscorrelated (? – SNR filtering, source set, other

reasons – under investigation) – possible reserve for EOP accuracy improving

• Further improvements:– software correlator– WVR– 2010 VLBI antennas (Zelenchukskaya, Badary)

• Colocation with GNSS, SLR (see poster )

THANK YOU!